CORDIS

The EU has formulated a vision of a competitive, innovative and sustainable Europe leading the transition towards a post-petroleum society while decoupling economic growth from resource depletion and negative environmental impacts, in which industries/SMEs, research organisations and universities will develop a bio-based economy for Europe.
UNRAVEL develops advanced pre-treatment, separation and conversion technologies for complex lignocellulosic biomass for high-value products in line with the EU vision. The pre-treatment technologies consist of feedstock pre-extraction and the FABIOLATM fractionation process using low-temperature aqueous acetone. UNRAVEL strives for valorisation of the feedstock extractives as high-value chemicals, pharma- and nutraceuticals can be present in the biomass. In addition, removal of non-lignocellulosic compounds by biomass pre-extraction is important to upgrade biomass for increased biorefinery feedstock flexibility and increased product purity. The subsequent downstream processing of the lignocellulosic components is performed using an innovative lignin precipitation technology for isolation of lignin and novel enzyme technologies for lignin depolymerisation as well as for enzymatic hydrolysis of the cellulose pulp. The isolated lignocellulosic components are subsequently converted into building blocks for high-value applications (xylonic acid, malic acid, acetone) and construction products (PUR/PIR insulation foam and bitumen additive for roofing materials). All process steps in the UNRAVEL project will be scaled up from lab (TRL 3) to pilot (TRL 5) and applications will be demonstrated at industrially relevant scale. An extensive techno-economic and sustainability assessment is done to assess the viability of the process.

Samples from a wide variety of feedstocks from forestry (stem wood, bark, branches and leaves from birch, beech and poplar), agriculture (wheat straw, corn stover, rapeseed straw, sunflower), municipal waste (road-side grass), energy crops (miscanthus), food-processing residues (cocoa pod husks, almond shells) were collected and extensively analysed for their lignocellulosic and extractives composition. Development of optimum pre-extraction conditions and the subsequent valorization of fine chemicals was conducted on a selection of feedstocks. Biomass lignocellulose enrichment was conducted in a larger-scale custom built pre-extraction unit. The fractionation of pre-extracted feedstocks resulted in reduced acid dose requirements for fractionation, increased monomeric sugar yield and a substantially higher lignin purity compared with fractionation of untreated feedstocks.
The scale-up results proved that the FABIOLA™ fractionation process is technically feasible at levels relevant for industrial production. UNRAVEL demonstrated that product yields and properties that were previously retrieved at laboratory scales can also be achieved at pilot scale. The obtained sugars have been fermented successfully to obtain xylonic acid and acetone at laboratory scale. The obtained lignin from the pilot experiment was converted to smaller lignin fragments using MetninTM technology. First lignin application tests for PUR/PIR insulation foam and bio-based bitumen for roofing applications are promising as a starting point for ongoing improvements on the properties of depolymerised lignin.
A suitable operating window for the continuous lignin precipitation process was obtained. The defined process operation conditions for controlled lignin precipitation were successfully applied in the newly developed lignin precipitation setup. More than 95 wt. % of the lignin was recovered as good filterable dry lignin powder and the process is ready for scale-up.
The outline of the interim process design for biomass fractionation into the products lignin, C6 sugars and C5 sugars has been set up. The interim process design focuses primarily on simplicity and robustness, rather than focusing on large optimisation of process and energy efficiency, which is being considered at a later stage. In addition, the latest insights into operational limits and equipment selection for lignin precipitation have been implemented. The settings for the sustainability assessment have been defined including the system boundaries and will be developed further in the next project phase.
Several project dissemination activities, networking events, press releases and online presence activities were initiated to build up the project visibility at the local, national and international level and to show how outcomes are relevant to the public. Therefore, the main focus has been put on raising awareness about UNRAVEL within the scientific and industrial community that is relevant for the project as well as to inform the interested general public and policy makers about our activities, aims and expected results and outcomes.

UNRAVEL aims to develop an innovative lignocellulosic value chain based on the FABIOLATM fractionation process and subsequent separation and conversion of the biopolymers to high value products, and to scale up these technologies from TRL3 to 5. A complete techno-economic and a sustainability assessment is performed on the integrated UNRAVEL value chain.
The ambition of the pre-extraction is to develop a techno-economically viable process to recover and purify valuable extractives and simultaneously minimise the interference of non-lignocellulosic constituents on subsequent fractionation. Currently, no such an integrated pre-extraction processes exist. These processes are evaluated from a sustainability point of view including technical and economic aspects.
The FABIOLA process using low-temperature aqueous acetone has been proven at lab-scale. Within UNRAVEL, the fractionation is demonstrated on a wide variety of biomass residues from the forestry, agricultural and food-processing industry. In addition, the fractionation technology is demonstrated at TRL 5 for these complex residues.
Precipitation and isolation of the lignin from the liquor can be performed by evaporation of the organic solvent or by dilution with water. State of the art methods have substantial practical drawbacks and/or a high energy demand. The progress of UNRAVEL beyond the state of the art is to develop a continuous lignin precipitation process with a lignin and solvent recovery of 95% and 99%, respectively. Currently, it is expected that these objectives can be demonstrated within the project.
Enzymatic lignin activation and depolymerisation towards smaller, more active and uniform fragments is highly challenging due to the recalcitrant nature and low water solubility of lignin in the conditions where enzymes typically perform with high efficiency. In UNRAVEL, novel enzymes with high efficiency in alkaline conditions (pH > 10) are applied. Lignin is fully water soluble under these alkaline conditions favouring conditions for enzymatic depolymerisation. The high solubility in combination with the less-condensed Fabiola lignin characteristics enables a high efficiency of enzymes towards lignin depolymerisation. This technology enables more economical and sustainable lignin valorisation towards a wider range of drop-in solutions as will be demonstrated for two construction product applications (PUR/PIR insulation foam and bio-based bitumen for roofing applications).